Many cells extrude cyclic AMP by an energy-dependent mechanism that is regulated by prostaglandins, is independent of adenylate cyclase and phosphodiesterase, is not readily saturable by cellular cyclic AMP accumulation, and seems to result from a specific transport system. We will employ avian red cells and S49 lymphoma cells to study cyclic AMP transport. We will first develop resealed ghost and vesicle preparations (inside-out and rightside-out), then employ them to establish the criteria characteristic of protein-mediated transport (saturability, specificity, antiport-symport-competition, modulation by protein-directed reagents, vectorial nature). The number of sites will be determined using the photoaffinity analog, 8-azido-cyclic AMP. We will assess the relation of extruded cyclic AMP to intracellular compartmentation by adenine pool labeling. We will determine the transport roles of protein kinase and phosphoproteins using PK- mutants of S49 cells and a variety of biochemical technics. Roles of other carriers and gradients will be explored using specific inhibitors and by exaggeration and abolition of gradients. Combined measurements of function and labeling (with the photoaffinity ligand) will permit biochemical characterization (pump or channel? integral protein? effects of lipids, orientation in membrane). We will attempt to purify the transport system by detergent solubilization, a polyadenylate-agarose hybridization technic, affinity chromatography, and selective extraction into phospholipid vesicles. We will attempt reconstitution of the transport system into defined phospholipid environments. We will also investigate the mode of interaction of PGA(1) to inhibit cyclic AMP efflux. Using S49 cells and Friend erytholeukemia cells, we hope to study genetic inducibility, constitutive synthesis, and genetic impairment of the transporter and to consider the import of cyclic AMP export on cell growth, cell cycle and red cell function, establishing the ontogeny of extrusion vis a vis other components of cyclic AMP metabolism in red cells. These studies will provide a detailed account of a neglected aspect of cyclic AMP metabolism and a newly described transport function that could modulate many effects of cyclic AMP accumulation (e.g., altered metabolic and secretory functions, positive inotropism, growth and differentiation.).